dt-bindings: serial: mediatek,uart: add MT8365

Add binding description for mediatek,mt8365-uart

Signed-off-by: Bernhard Rosenkränzer <bero@baylibre.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20230309213501.794764-3-bero@baylibre.com


Signed-off-by: Rob Herring <robh@kernel.org>